This invention relates to an automatic sample delivery apparatus for use in an automatic chemical analyzer in which one or more emergency samples and standard samples can be predominantly delivered by interrupting the delivery of successive routine samples.
Various types of automatic chemical analyzers have been used for automatically analyzing and testing components contained in various samples, such as serum and urine samples. In general, samples to be analyzed are contained in sample vessels or tubes which are set in an automatic sample delivery apparatus, usually called a sampler. In the sampler the sample vessels are fed along a given path through a sample sucking position at which a given amount of a sample contained in a sample vessel just indexed to the position is sucked into a sucking probe. The sample thus sucked in the probe is delivered or discharged into one or more reaction vessels. In such an automatic chemical analyzer, a number of sample vessels set in the sampler are successively indexed into the sample sucking position, and successive samples are delivered into reaction vessels in a given order. In order to analyze one or more emergency samples and standard samples for effecting the calibration, the emergency samples and standard samples have to be predominantly delivered by interrupting the normal delivery of successive routine samples.
In German Patent Application Laid-Open Publication (Offenlegungschrift) No. 33 06 491 there is disclosed an automatic chemical analyzer in which an emergency sample holder is swingably arranged above the feeding path of the routine samples at the sample sucking position and, when an emergency sample is to be analyzed, a sample vessel containing the emergency sample is set in the holder and the holder is swung into a position which is aligned with the sample sucking position. In such an apparatus, since the emergency sample is set at a level above the feeding path of routine samples, the emergency sample could not be identified by a device for identifying the routine samples, so that the emergency sample might not be accurately identified. Therefore, test results of the emergency samples and standard samples might not be clearly distinguished from each other as well as from those of the routine samples. Further, the sample sucking probe has to pick up samples both at the lower routine sample sucking position and at the upper emergency sample sucking position, and therefore the probe must move over a long distance. As a result, the sample sucking device, including the probe and its driving mechanism, becomes large in size and complicated in construction. Further, the sample delivery precision is liable to be unacceptable.
In European Patent Application Publication No. 0035320 and U.S. Pat. No. 4,276,051, there are described automatic chemical analyzers in which routine samples are set along outer circles on a turntable and emergency and standard samples are set along the innermost circle on the turntable. A sample sucking probe is arranged movably over substantially a radius of the turntable so that an emergency sample can be sucked into the probe. Also, in such an analyzer ID marks such as bar codes provided on the emergency sample vessels could not be read out by the same ID reading device for reading ID marks on the routine sample vessels. Further, since the sucking probe has to move over a relatively long path above the turntable, the sample sucking device is liable to be large and complicated. Moreover, during the delivery of the emergency samples, the emergency samples sucked into the probe might drop into routine sample vessels to cause contamination. Such contamination of samples results in serious errors of measurement.